Fuel Line Question

Designs for inboard or outboard power

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Fuel Line Question

Postby Onplane » Mon May 22, 2017 8:19 am

I am in the process of installing my Moeller permanent fuel tank for my Malahini and had a couple questions concerning the fuel line...

The supply line coming out of the tank is 1/4" NPT. I need to get a fuel line to run from there to my water/oil separating can filter and then up to the outboard fuel pickup.

Not really knowing much but what I've been able to read online... it sounds like I want to buy the best fuel line that holds up well to possible ethanol degradation. I've heard good things about both Mercury OEM fuel line and one called "Trident."

The Trident, however, is a black hose, which I guess is only rated for below deck applications, whereas the grey line (in this case the Merc OEM) is approved for above deck.

Additionally, the Trident is 3/8" ID, and the Merc is 5/16" ID. (I can get a 1/4 NPT for either size though, and I'm pretty sure the lines on the actual outboard aren't any bigger than 5/16" anyway).

I plan to be a weekend warrior with this boat, so it will be stored in my garage most of the time but fuel could possibly sit in the lines for longer durations...

With that in mind... and trying not to spend more $$ than necessary, how should I hook it up?

Should I use the Trident from the tank barb to the filter, then the grey line from the filter to the engine because filter to engine is partially above deck?

Or can I run the Trident for the whole line above/below because I won't be using it very often?

Or, for the sake of cost, can I just run the OEM Merc grey stuff for the whole line?

Just trying to get the thoughts from more experienced members... Thanks!

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Re: Fuel Line Question

Postby vupilot » Mon May 22, 2017 8:45 am

I just went to NAPA and bought fuel line by the foot. Its black and fine for ethanol as almost any fuel line from the last 20 years is. Its been working fine for almost 7 years now. I run straight to the outboard, no separator or filter. The carb has a very fine screen before the fuel goes to the carb and I have never found anything in the screen.

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Re: Fuel Line Question

Postby Hercdrvr » Mon May 22, 2017 10:58 am

I too ran a standard squeeze bulb and line, added an inline fuel filter from the parts store. $5 and 5 min insurance policy. Used the clear case filter, something reassuring about seeing the gas flowing as I'm squeezing the bulb.
In my word fuel line is fuel line, if it rots I replace it. Hasn't been an issue yet.
Matt B

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Mr Hot Rod
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Re: Fuel Line Question

Postby Mr Hot Rod » Mon May 22, 2017 10:45 pm

You may find more info in the following post :

Hope this helps !
Paul Kane
Kane Custom Boats Ltd.
Chelsea, Quebec

Building the Glen-L Hot Rod : http://www.kanecustomboats.com
Glen-L Hot Rod build thread
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Bob Perkins
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Re: Fuel Line Question

Postby Bob Perkins » Tue May 23, 2017 4:38 am

I purchased automotive fuel line too..
No issues..

You do want it to me accessible however - everything fails eventually.
Bob Perkins

All the Fun Stuff

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Re: Fuel Line Question

Postby hoodman » Thu May 25, 2017 7:57 pm

You can also use sta bill or star tron fuel treatment in your gas. They help a lot if the gas sits unused for long periods. One of the big problems with ethanol in fuel is that it attracts moisture. Then you have water in your gas. The fuel additives that I mentioned do something chemically to allow the water to be able to pass through the motor and be "burned up" with the fuel. I could be wrong on some of that.

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Re: Fuel Line Question

Postby garrech » Thu May 25, 2017 8:48 pm

Stabil is good stuff. When the end of the season is near, I add it to the fuel so that it gets in the fuel lines and the engine before sitting up all winter. I also recommend pure gas i.e. no ethanol gas if you have it in your area.

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